Extras - Impressive rigging demo reel

I came across this demo reel and found it very interesting. The rigs done by this guy are very detailed and well done. The muscleman's rig was impressive as it shows the muscles working with every movement. There are also cartoony rigs, animal rigs, as well as mythical rigs. I learnt that, although animals have different joints from humans, some parts work similarly, such as the bird's talons as compared to the human toes.